The present invention relates generally to medical electrical leads, and more particularly to electrode assemblies for use on medical electrical leads.
Previously known electrodes for use with medical electrical leads have generally been connected to the conductor of the electrical lead by means of a weld, as illustrated in U.S. Pat. No. 3,348,548 by means of a crimp as illustrated in U.S. Pat. No. 4,338,947 or by means of a swaging core as illustrated in U.S. Pat. No. 4,328,812. Adhesive attachment has also been used, as shown in U.S. Pat. No. 3,568,660. The use of welds to attach electrodes to medical electrical leads has generally fallen out of favor, due to the high temperatures required to effect the weld, and due to the difficulty of sealing the lead around the weld. More popular are the crimped and swaged electrodes. However, the crimping and swaging methods of attachment, as illustrated in the above cited patents, have the inherent disadvantage that the connection is made inside the electrode structure. As a result, the integrity of the attachment cannot be inspected visually. Because these electrodes typically employ metals which are not easily penetrated by x-rays, a number of sample assemblies must be tested destructively to mechanically determine the strength of the attachments.